As a method for performing qualitative/quantitative analysis of a biological sample, such as blood or urine, two representatives are a colorimetric analysis that uses a reagent which reacts with a component to be measured in the sample to result in color change, and measures the color change by a photometer, and an immunoassay that adds labels directly or indirectly to a substance which binds specifically to a component to be measured, and counts the labels. In recent years, analysis of a biological sample performed by a physicochemical method using a mass analyzer has been attempted, and the scope of application thereof is expected to increase in the future.
To examine/analyze a component contained in an organism-derived sample, such as blood, blood serum, blood plasma, cell tissue, or urine, it is difficult to achieve detection at high accuracy, if many kinds of components are simultaneously measured, since many components of more than several tens of thousands of kinds coexist in biological components. Therefore, it is preferred that a pretreatment for concentrating/purifying a biological sample be performed. To subject a low-molecular compound, such as a drug, to laboratory analysis using a mass spectrometer, liquid chromatography (LC) is commonly performed as the pretreatment to separate a target component. Simpler methods for extracting a component are liquid-liquid extraction and solid-phase extraction techniques. In a typical solid-phase extraction technique, the target component is adsorbed to an adsorbent having various properties that is filled in a syringe-like or plate-like container. After washing and removing impurities from the adsorbed components, the target component is eluted and collected from the adsorbent. As compared with the LC separation, the solid-phase extraction method is inferior in component separation performance, but can collect a target component in a short time and with low cost.
To perform the treatment of solid-phase extraction, not only a solid-phase extraction column or plate but also a container for collecting an extracted component is required. In particular, to automate the treatment of solid-phase extraction for the purpose of clinical analysis or the like, it is required to switch collection containers or flow passages according to an operational step so that waste liquid generated in the treatment of solid-phase extraction and extracted matter can be segregated. For example, to apply a turntable system, which is applied to a common automatic immunoassay analyzer or the like, to an automatic apparatus for the treatment of solid-phase extraction, a problem is how to simply achieve segregational collection of waste liquid and extracted matter.
Collection of extracted matter is commonly performed by a fraction collector. The fraction collector is an apparatus to obtain (fractionate) different substances in different containers by utilizing the fact that a period of time of elution of a substance when the substance passes through a column of a liquid chromatography depends on physical/chemical properties of the substance. That is, the apparatus adopts such a mechanism that collection containers are preliminarily arranged on the fraction collector, and collections of waste liquid and extracted matter are performed with a certain timing (for example, a period of time, or the number of drops) (see Patent Documents 1 to 5).
Further, an apparatus for automating a solid-phase extraction treatment is commercially available (see Patent Document 6). Such an apparatus is used, for example, for high-throughput screening of a candidate drug in the field of drug discovery, or the like. Therefore, a solid-phase extraction device used in this apparatus has a plate-like shape, such as a 96 well plate, where independent solid-phase extractions in individual wells are performed simultaneously for all the wells in a plate.